Camera lens

ABSTRACT

A camera lens is disclosed. The camera lens includes seven piece ultra-thin and high-luminous flux wide angle lenses with excellent optical properties as follows: a first lens with positive refractive power; a second lens with negative refractive power; a third lens with negative refractive power; a fourth lens with positive refractive power; a fifth lens with positive refractive power; a sixth lens with positive or negative refractive power, and a seventh lens with negative refractive power which are arranged in an order from an object side to an image side. The camera lens satisfies specified conditions.

FIELD OF THE INVENTION

The present invention relates to a camera lens, and more particularly toa camera lens very suitable for mobile phone camera module and WEBcamera lens etc. equipped with high-pixel camera elements such as CCD,CMOS etc.

DESCRIPTION OF RELATED ART

In recent years, various camera devices equipped with camera elementssuch as CCD, CMOS are extensively popular. Along with development oncamera lens toward miniaturization and high performance, ultra-thin andhigh-luminous flux (Fno) wide angle camera lenses with excellent opticalproperties are needed.

The technology related to the camera lens composed of seven pieceultra-thin and high-luminous flux (Fno) wide angle lenses with excellentoptical properties is developed gradually. The camera lens mentioned inthe proposal of prior reference documents 1, 2, 3 is composed of sevenpiece lenses which are arranged sequentially from the object side asfollows: a first lens with positive refractive power; a second lens withnegative refractive power; a third lens with negative refractive power;a fourth lens with positive refractive power and a fifth lens withpositive refractive power; a sixth lens with positive refractive power,a seventh lens with negative refractive power.

The camera lens disclosed in embodiments 5 and 9 of the prior referencedocument 1 has Fno=1.44 bright, but refractive power distribution of thefifth lens is insufficient and the shape of the fifth lens is improper;so it is not sufficiently ultra-thin.

The camera lens disclosed in embodiment 3 of prior reference document 2has Fno=1.44 bright, but refractive power distribution of the fifth lensis insufficient and the shape of the fifth lens is improper; so it isnot sufficiently ultra-thin.

The camera lens disclosed in embodiment 5 of prior reference document 3has Fno=1.45 bright, but refractive power distribution of the fifth lensis insufficient and the shape of the fifth lens is improper; so it isnot sufficiently ultra-thin.

The camera lens mentioned in the proposal of prior reference document 4is composed of seven piece lenses which are arranged sequentially fromthe object side as follows: a first lens with positive refractive power;a second lens with negative refractive power; a third lens with negativerefractive power; a fourth lens with positive refractive power, a fifthlens with positive refractive power; a sixth lens with negativerefractive power, a seventh lens with negative refractive power.

According to the camera lens disclosed in embodiment 10 of priorreference document 4, refractive power distribution of the fifth lens isinsufficient and the shape of the fifth lens is improper. Brightness andultra-thin are both insufficient.

PRIOR REFERENCE DOCUMENTS

[Prior Reference Document 1] Japan Patent Publication No. JP2015-072403;

[Prior Reference Document 2] Japan Patent Publication No. JP2015-072405;

[Prior Reference Document 3] Japan Patent Publication No. JP2015-114505;

[Prior Reference Document 4] Japan Patent Publication No. JP2015-055728.

Therefore, it is necessary to provide a novel camera lens to solve theabove-mentioned technical problem.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiments can be better understood with referenceto the following drawings. The components in the drawings are notnecessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the present disclosure. Moreover,in the drawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is an illustrative structure of a camera lens LA of the presentdisclosure.

FIG. 2 is an illustrative structure of a camera lens LA in accordancewith a first embodiment (Embodiment 1) of the present disclosure.

FIG. 3 is a Longitudinal Aberration diagram of the camera lens LA in theEmbodiment 1.

FIG. 4 is a Lateral Color Aberration diagram of the camera lens LA inthe Embodiment 1.

FIG. 5 is a Field Curvature Distortion of the camera lens LA in theEmbodiment 1.

FIG. 6 is an illustrative structure of a camera lens LA in accordancewith a second embodiment (Embodiment 2) of the present disclosure.

FIG. 7 is a Longitudinal Aberration diagram of the camera lens LA in theEmbodiment 2.

FIG. 8 is the Lateral Color Aberration diagram of the camera lens LA inthe Embodiment 2.

FIG. 9 is a Field Curvature Distortion of the camera lens LA in theEmbodiment 2.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The present invention will hereinafter be described in detail withreference to exemplary embodiments. To make the technical problems to besolved, technical solutions and beneficial effects of present disclosuremore apparent, the present disclosure is described in further detailtogether with the figures and the embodiments. It should be understoodthe specific embodiments described hereby is only to explain thisdisclosure, not intended to limit this disclosure.

A camera lens of the present disclosure shall be explained by referringto the design drawings. Referring to FIG. 1, a camera lens LA comprisesseven piece lenses which are arranged in an order from an object side toan imaging surface side, including a first lens L1, a second lens L2, athird lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and aseventh lens L7. A glass plate GF is arranged between the seventh lensL7 and the imaging surface. And a glass cover or an optical filterhaving the function of filtering IR can serve as the glass plate GF.Moreover, it shall be OK if no glass plate GF is arranged between theseventh lens L7 and the imaging surface.

The first lens has positive refractive power; the second lens hasnegative refractive power; the third lens has negative refractive power;the fourth lens has positive refractive power; the fifth lens haspositive refractive power; the sixth lens has positive or negativerefractive power; and the seventh lens has negative refractive power.Moreover, the surfaces of the seven lenses should be designed as theaspheric shape preferably in order to correct the aberration well.

The camera lens LA satisfies the following conditions (1)˜(2):0.10≦f2/f3≦0.50  (1);0.30≦f5/f≦1.00  (2); where,f: overall focal distance of the camera lensf2: focal distance of the second lens L2f3: focal distance of the third lens L3f5: focal distance of the fifth lens L5

Ratio of focal distance of the second lens to the third lens both withnegative refractive power is specified in condition (1). When exceedingrange of condition (1), it is difficult to correct the chromaticaberration.

Therefore, numerical range of condition (1) should be set within thenumerical range of the following condition (1-A) preferably,0.15≦f2/f3≦0.25  (1-A)

The positive refractive power of the fifth lens L5 is specified in thecondition (2). Moreover, the development of ultra-thin and wide angletrend of Fno≦1.8 cannot be implemented easily outside the range of thecondition (2).

Therefore, numerical range of condition (2) should be set within thenumerical range of the following condition (2-A) preferably,0.58≦f5/f≦0.73  (2-A)

The sixth lens L6 has positive or negative refractive power and meetsthe following condition (3).10.00≦|f6|/f≦100.00  (3);Where,f: overall focal distance of the camera lensf6: focal distance of the sixth lens L6

The positive or negative refractive power of the sixth lens L6 isspecified in the condition (3). Moreover, the development of ultra-thinand wide angle trend of Fno≦1.8 cannot be implemented easily outside therange of the condition (3).

Therefore, numerical range of condition (3) should be set within thenumerical range of the following condition (3-A) preferably,14.00≦|f6|/f≦80.00  (3-A).

Abbe numbers of the second lens L2, the third lens L3 and the sixth lensL6 meet following conditions (4)˜(6):18.00≦ν2≦32.00  (4);18.00≦ν3≦32.00  (5);18.00≦ν6≦32.00  (6);where,ν2: abbe number of the second lens L2ν3: abbe number of the third lens L3ν6: abbe number of the sixth lens L6

Abbe numbers of the second lens L2, the third lens L3 and the sixth lensL6 are specified in condition (4)˜(6). Correction of chromaticaberration on axis and outside of axis becomes easy by setting thenumerical values within the range of conditions (4)˜(6).

Because seven lenses of camera Lens all have the stated formation andmeet all the conditions, so it is possible to produce a camera lenswhich is composed of seven lenses with excellent optional properties,TTL(optical length)/IH(image height)≦1.55, ultrathin, wide angle 2ω≧75°,Fno≦1.8.

The camera lens LA of the invention shall be explained below by usingthe embodiments. Moreover, the symbols used in all embodiments are shownas follows. And mm shall be taken as the units of the distance, theradius and the center thickness.

f: overall focal distance of the camera lens LA

f1: focal distance of the first lens L1

f2: focal distance of the second lens L2

f3: focal distance of the third lens L3

f4: focal distance of the fourth lens L4

f5: focal distance of the fifth lens L5

f6: focal distance of the sixth lens L6

f:7 focal distance of seventh lens L7

Fno: F value

2ω: total angle of view

S1: aperture

R: curvature radius of optical surface, central curvature radius whenthe lens is involved

R1: curvature radius of the first lens L1's object side surface

R2: curvature radius of the first lens L1's image side surface

R3: curvature radius of the second lens L2's object side surface

R4: curvature radius of the second lens L2's image side surface

R5: curvature radius of the third lens L3's object side surface

R6: curvature radius of the third lens L3's image side surface

R7: curvature radius of the fourth lens L4's object side surface

R8: curvature radius of the fourth lens L4's image side surface

R9: curvature radius of the fifth lens L5's object side surface

R10: curvature radius of the fifth lens L5's image side surface

R11: curvature radius of the sixth lens L6's object side surface

R12: curvature radius of the sixth lens L6's image side surface

R13: curvature radius of the seventh lens L7's object side surface

R14: curvature radius of the seventh lens L7's image side surface

R15: curvature radius of the glass plate GF's object side surface

R16: curvature radius of the glass plate GF's image side surface

d: center thickness of lenses or the distance between lenses

d0: distance from the open aperture S1 to the object side of the firstlens L

d1: center thickness of the first lens L1

d2: distance from the image side surface of the first lens L1 to theobject side surface of the second lens L2

d3: center thickness of the second lens L2

d4: axial distance from the image side surface of the second lens L2 tothe object side surface of the third lens L3

d5: center thickness of the third lens L3

d6: axial distance from the image side surface of the third lens L3 tothe object side surface of the fourth lens L4

d7: center thickness of the fourth lens L4

d8: axial distance from the image side surface of the fourth lens L4 tothe object side surface of the fifth lens L5

d9: center thickness of the fifth lens L5

d10: axial distance from the image side surface of the fifth lens L5 tothe object side surface of the sixth lens L6

d11: center thickness of the sixth lens L6

d12: axial distance from the image side surface of the sixth lens L6 tothe object side surface of the seventh lens L7

d11: center thickness of the seven lens L7

d14: axial distance from the image side surface of the seventh lens L7to the object side surface of the glass plate GF

d15: center thickness of the glass plate GF

d16: axial distance from the image side surface to the imaging surfaceof the glass plate GF

nd: refractive power of line d

nd1: refractive power of line d of the first lens L1

nd2: refractive power of line d of the second lens L2

nd3: refractive power of line d of the third lens L3

nd4: refractive power of line d of the fourth lens L4

nd5: refractive power of line d of the fifth lens L5

nd6: refractive power of line d of the sixth lens L6

nd7: refractive power of line d of the seventh lens L7

nd8: refractive power of line d of the glass plate GF

νd: abbe number

ν1: abbe number of the first lens L1

ν2: abbe number of the second lens L2

ν3: abbe number of the third lens L3

ν4: abbe number of the fourth lens L4

ν5: abbe number of the fifth lens L5

ν6: abbe number of the sixth lens L6

ν1: abbe number of the seventh lens L7

ν8: abbe number of the glass plate GF

TTL: optical length (axial distance from object side surface to theimaging surface of the first lens L1)

LB: axial distance (including the thickness of the glass plate GF) fromthe image side surface to the imaging surface of the seventh lens L7;

IH: image heighty=(x2/R)/[1+{1−(k+1)(x2/R2)}½]+A4x4+A6x6+A8x8+A10x10+A12x12+A14x14+A16x16  (7)Wherein R indicates the curvature radius on the axle; k indicates theconical coefficient; and A4, A6, A8, A10, A12, A14 and A16 indicates thecoefficients of the aspheric surface

For convenience sake, the aspheric surface shown in the formula (7)shall be taken as the aspheric surfaces of all lens surfaces. However,the invention shall be not limited to the polynomial form of theaspheric surface shown in the condition (7).

Embodiment 1

The configuration structure diagram of the camera lens LA in theEmbodiment 1 is shown in the FIG. 2. Moreover, the data includingcurvature radius R of the object side surfaces and the image sidesurfaces, center thicknesses of the lenses, the distances d among thelenses, refractive powers nd and abbe numbers νd of the lens L1-L7 inthe Embodiment 1 are shown in the Table 1, wherein the camera lens LA isformed by the lens L1-L7; and the data including conical coefficients kand aspheric coefficients are shown in the Table 2.

TABLE 1 R d nd vd S1 ∞ d0 = −0.475 R1 1.73679 d1 =  0.774 nd1 1.5441 v156.12 R2 37.44769 d2 =  0.052 R3 11.71991 d3 =  0.204 nd2 1.6422 v222.41 R4 3.30101 d4 =  0.495 R5 −5.05613 d5 =  0.217 nd3 1.6422 v3 22.41R6 −6.35357 d6 =  0.051 R7 11.11572 d7 =  0.509 nd4 1.5441 v4 56.12 R826.85452 d8 =  0.451 R9 −6.86869 d9 =  0.515 nd5 1.5352 v5 56.12 R10−1.36187 d10 =  0.065 R11 −6.53333 d11 =  0.365 nd6 1.6422 v6 22.41 R12−6.46586 d12 =  0.286 R13 −3.08181 d13 =  0.319 nd7 1.5352 v7 56.12 R142.21835 d14 =  0.500 R15 ∞ d15 =  0.210 nd8 1.5168 v8 64.17 R16 ∞ d16 = 0.320

TABLE 2 conical coefficient aspheric coefficient k A4 A6 A8 A10 A12 A14A16 R1 −2.6717E−01 8.6506E−03 7.6241E−03 −2.9703E−03 6.8153E−041.6490E−03 8.9491E−04 −1.0337E−03 R2 0.0000E+00 9.7177E−03 −3.3264E−035.8474E−03 8.5766E−04 −3.8927E−03 −3.1564E−03 2.1050E−03 R3 −2.6816E+00−1.0352E−02 1.0703E−02 4.7468E−03 −7.5022E−03 −4.1229E−04 1.2876E−038.0402E−04 R4 −1.3180E+00 2.6635E−03 2.7988E−03 1.1321E−02 −7.8714E−04−7.0065E−03 −4.4921E−03 1.3476E−02 R5 1.7784E+01 −4.2601E−03 −2.8602E−02−6.4579E−03 7.2876E−03 6.5086E−03 5.2106E−04 5.7701E−03 R6 2.3798E+01−6.8949E−04 −1.8989E−02 1.7447E−03 8.7524E−03 5.7817E−03 1.9411E−03−8.9159E−04 R7 0.0000E+00 −6.2436E−02 7.2765E−03 4.0155E−03 8.1038E−044.9297E−05 −2.7730E−05 −9.9144E−05 R8 0.0000E+00 −6.2656E−02 −3.6090E−039.1813E−05 −3.2632E−04 7.2576E−05 1.3011E−04 2.2548E−05 R9 7.7515E+00−2.6910E−02 −8.4713E−03 9.2514E−04 −1.2678E−03 −1.0249E−04 7.0432E−053.8018E−05 R10 −3.5242E+00 −3.3545E−02 1.2297E−02 −1.6295E−04 3.5213E−05−4.6205E−05 −8.1781E−06 −1.5223E−07 R11 1.0104E+00 −2.6801E−03−1.2654E−04 1.2961E−05 3.0026E−06 1.7191E−07 2.9472E−08 −1.8205E−09 R121.4678E+00 −8.3931E−04 −5.4876E−05 −1.3307E−05 −9.4894E−07 8.4646E−084.0654E−08 1.4451E−08 R13 −1.3052E−01 1.6728E−04 2.6737E−03 4.2251E−05−1.2348E−05 −6.4263E−07 1.0289E−08 6.5823E−09 R14 −1.5549E+01−2.3403E−02 3.1358E−03 −4.3484E−04 1.7355E−05 5.6217E−07 1.5247E−081.5063E−09

The values in the embodiments 1 and 2 and the values corresponding tothe parameters specified in the conditions (1)-(5) are shown in thesubsequent Table 6.

The Embodiment 1 meets the conditions (1)-(5), as shown in Table 6.

Refer to FIG. 3 for Longitudinal Aberration of the camera lens LA in theEmbodiment 1, refer to FIG. 4 for Lateral Color Aberration of it, andsee FIG. 5 for curvature of field and distortion of it. Further, thecurvature of field S in the FIG. 5 is the one in the sagittal direction,and T is the one in the direction of meridian, as well as in theEmbodiment 2. Moreover, the camera lens LA in the embodiment 1 involvesthe ultra-thin wide angle camera lens having high luminous flux as shownin FIGS. 3-5, wherein 2ω=76°, TTL/IH=1.535, Fno=1.74; therefore, it isno wonder that this lens has these excellent optical properties.

Embodiment 2

The configuration structure diagram of the camera lens LA in theEmbodiment 2 is shown in the FIG. 6. Moreover, the curvature radius ofthe object side surfaces and the image side surfaces, the centerthicknesses of the lenses, the distances d among the lenses, therefractive powers nd and abbe numbers νd of the lens L1-L7 in theEmbodiment 2 are shown in the Table 3, wherein the camera lens LA isformed by the lens L1-L7; and the conical coefficients k and asphericcoefficients are shown in the Table 4.

TABLE 3 R d nd vd S1 ∞ d0 = −0.399 R1 1.77698 d1 =  0.634 nd1 1.5441 v156.12 R2 50.89532 d2 =  0.053 R3 10.50150 d3 =  0.210 nd2 1.6510 v221.51 R4 3.36985 d4 =  0.481 R5 −4.98071 d5 =  0.225 nd3 1.6422 v3 22.41R6 −6.37878 d6 =  0.051 R7 9.73268 d7 =  0.507 nd4 1.5441 v4 56.12 R812.57164 d8 =  0.392 R9 −10.06326 d9 =  0.611 nd5 1.5352 v5 56.12 R10−1.22163 d10 =  0.053 R11 −9.70142 d11 =  0.310 nd6 1.5855 v6 29.91 R12−12.40696 d12 =  0.286 R13 −3.02209 d13 =  0.328 nd7 1.5352 v7 56.12 R142.07780 d14 =  0.500 R15 ∞ d15 =  0.210 nd8 1.5168 v8 64.17 R16 ∞ d16 = 0.353

TABLE 4 conical coefficient aspheric coefficient k A4 A6 A8 A10 A12 A14A16 R1 −2.4629E−01 8.2979E−03 7.6019E−03 −4.7157E−03 4.2144E−042.9451E−03 1.3204E−03 −2.5303E−03 R2 0.0000E+00 1.2431E−02 −5.7931E−034.5976E−03 −5.0813E−05 −5.8518E−03 −3.2053E−03 3.1702E−03 R3 −4.2420E+00−1.2083E−02 1.0001E−02 1.8548E−03 −9.8072E−03 −1.5566E−03 1.4001E−033.5861E−03 R4 −3.4925E+00 −4.3957E−03 −4.9223E−03 3.7174E−03 −6.6181E−03−8.8995E−03 −4.1366E−03 1.1910E−02 R5 1.8526E+01 −1.1480E−02 −3.8868E−02−2.1191E−02 −2.5932E−03 4.8983E−03 5.1706E−03 1.1960E−02 R6 2.5105E+012.5280E−03 −2.4560E−02 −1.2118E−03 9.1151E−03 7.6258E−03 3.4165E−03−7.6629E−04 R7 0.0000E+00 −6.7882E−02 1.2195E−02 6.7487E−03 4.2506E−04−5.3341E−04 −2.0007E−04 6.6490E−05 R8 0.0000E+00 −7.3033E−02 −7.6011E−06−1.1057E−04 −6.4387E−04 −6.3813E−05 1.7084E−04 6.3558E−05 R9 1.8505E+01−3.9669E−02 −3.5198E−03 9.6396E−04 −1.6921E−03 −2.2973E−04 7.7450E−056.5205E−05 R10 −3.2116E+00 −5.3237E−02 1.5821E−02 4.4059E−04 3.0528E−05−6.4677E−05 −1.2171E−05 5.6538E−07 R11 1.0565E+01 −1.3447E−02−4.0864E−04 1.3071E−05 3.3941E−06 2.8496E−06 7.6167E−07 −3.4169E−08 R121.2509E+01 −1.1585E−02 1.8557E−04 3.0703E−05 9.6976E−07 −1.1777E−06−5.9351E−08 7.5700E−08 R13 −1.1273E−01 2.7039E−03 2.7019E−03 3.7461E−05−1.3600E−05 −6.9287E−07 2.0207E−08 9.9132E−09 R14 −1.3904E+01−2.4062E−02 3.5291E−03 −4.8138E−04 1.9758E−05 1.0185E−06 1.9068E−08−4.2704E−09

The Embodiment 2 meets the conditions (1)-(5), as shown in Table 6.

See FIG. 7 for Longitudinal Aberration of the camera lens LA in theEmbodiment 2, see FIG. 8 for Lateral Color Aberration of it, and seeFIG. 9 for curvature of field and distortion of it. Moreover, the totalangle of view is involved in the camera lens LA in the Embodiment 2 asshown in FIGS. 7-9, and the lens refers to the ultra-thin wide anglecamera lens having high luminous flux, wherein 2ω=80.0°, TTL/IH=1.498,Fno=1.78; therefore, it is no wonder that this lens has these excellentoptical properties.

The values in all embodiments and the values corresponding to theparameters specified in the conditions (1)-(5) are shown in the Table 6.Moreover, the units including 2ω(°), f(mm), f1 (mm), f2 (mm), f3 (mm),f4 (mm), f5 (mm), f6 (mm), f7 (mm), TTL(mm), LB(mm) and IH(mm) are shownin the Table 5, respectively.

TABLE 5 Embodiment 1 Embodiment 2 Condition f2/f3 0.175 0.204 1 f5/f0.702 0.621 2 |f6|/f 71.472 19.434 3 ν2 22.41 21.51 4 ν3 22.41 22.41 5ν6 22.41 29.91 6 Fno 1.74 1.78 2ω 76.0 80.0 TTL/IH 1.535 1.498 f 4.3794.083 f1 3.322 3.369 f2 −7.225 −7.713 f3 −41.257 −37.766 f4 34.46774.524 f5 3.074 2.537 f6 312.977 −79.350 f7 −2.361 −2.250 TTL 5.3335.204 LB 1.030 1.063 IH 3.475 3.475

It is to be understood, however, that even though numerouscharacteristics and advantages of the present exemplary embodiments havebeen set forth in the foregoing description, together with details ofthe structures and functions of the embodiments, the disclosure isillustrative only, and changes may be made in detail, especially inmatters of shape, size, and arrangement of parts within the principlesof the invention to the full extent indicated by the broad generalmeaning of the terms where the appended claims are expressed.

What is claimed is:
 1. A camera lens, comprising in order from an objectside to an image side: a first lens with positive refractive power; asecond lens with negative refractive power; a third lens with negativerefractive power; a fourth lens with positive refractive power; a fifthlens with positive refractive power; a sixth lens with positive ornegative refractive power; a seventh lens with negative refractivepower; wherein the camera lens satisfying the following conditionformulas (1)˜(2) and (4)˜(6):0.10≦f2/f3≦0.50  (1);0.30≦f5/f≦1.00  (2);18.00≦ν2=32.00  (4);18.00≦ν3≦32.00  (5);18.00≦ν6≦32.00  (6); where, f: overall focal distance of the cameralens; f2: focal distance of the second lens; f3: focal distance of thethird lens; f5: focal distance of the fifth lens; ν2: abbe number of thesecond lens; ν3: abbe number of the third lens; ν6: abbe number of thesixth lens.
 2. The camera lens as described in claim 1 furthersatisfying the following condition (3):10.00≦|f6|/f≦100.00  (3); where, f: overall focal distance of the cameralens; f6: focal distance of the sixth lens.